The present invention relates to a hand-operated, portable stapler, particularly for office use.
Staplers of this type generally include a base plate provided at its free end with an anvil for bending the staple legs, a staple magazine pivotally connected to the other end of the base plate to be pivotal in a plane perpendicular to the base plate, and an actuating lever pivotally connected by means of a separate bearing to the staple magazine to also be pivotal in a plane perpendicular to the base plate to actuate a staple driver to drive the staples from the staple magazine. The stapler is in addition provided with lateral guide surfaces disposed between the base plate and the staple magazine or between the staple magazine and the actuating lever. One such structure is disclosed in British Pat. No. 619,300.
In the stapler of the above-mentioned type, the three main components, i.e. base plate, staple magazine and actuating lever, are each made of a metallic material. These three main parts are connected together in pairs by separate, riveted pivot members defining pivot axes. Guide surfaces are provided between the staple magazine and the base plate in the form of longitudinal ribs which protrude upwardly from the base plate into the pivoting range of the staple magazine, with the sides of the ribs resting against the staple magazine. These longitudinal ribs create inconvenience if the stapler is to be used as a staple "gun", i.e. if the base plate is pivoted by about 180.degree. or more out of the operating position and thus is made ineffective, to drive staples into a thick substrate, for example to attach sheets of paper to walls or to wooden supports.
It is also known to releasably connect the staple magazine of a stapler to the base plate of the stapler by a catch joint connection, as disclosed in U.S. Pat. Nos. 1,507,775 and 1,740,322, and to fabricate the actuating lever of a stapler of the above-mentioned type as an injection-molded plastic unit, as disclosed in British Pat. No. 967,415.